1. Heat the olive oil on very low heat in an omelette pan, and sauté the garlic and lemon zest for just a few seconds, being careful that they do not turn brown.
2. Add the courgette slices, increase the heat to medium, stir, cover the pan with a lid, and cook for a few minutes until soft.
3. Beat the eggs, add the salt, pepper and milk, and whisk again thoroughly.
4. Remove the lid from the pan, pour in the eggs evenly and let the omelette cook for 5 – 7 minutes.
5. Sprinkle the omelette with oregano, and dot the surface with the feta cubes and olives, spreading them around evenly.
6. Place the pan under a low grill for just a few minutes, until the omelette is slightly brown at the edges, a little risen and completely cooked through – but make sure that the feta pieces or olives don’t burn. Serve warm, cut into wedges.